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42 #include "qsgpointattractor_p.h"
46 QSGPointAttractorAffector::QSGPointAttractorAffector(QSGItem *parent) :
47 QSGParticleAffector(parent), m_strength(0.0), m_x(0), m_y(0)
48 , m_physics(Velocity), m_proportionalToDistance(Linear)
52 bool QSGPointAttractorAffector::affectParticle(QSGParticleData *d, qreal dt)
54 if (m_strength == 0.0)
56 qreal dx = m_y - d->curX();
57 qreal dy = m_x - d->curY();
58 qreal r = sqrt((dx*dx) + (dy*dy));
59 qreal theta = atan2(dy,dx);
61 switch (m_proportionalToDistance){
63 ds = (m_strength / qMax<qreal>(1.,r*r)) * dt;
65 case Linear://also default
67 ds = (m_strength / qMax<qreal>(1.,r)) * dt;
77 d->setInstantaneousAX(d->ax + dx);
78 d->setInstantaneousAY(d->ay + dy);
80 case Velocity: //also default
82 d->setInstantaneousSX(d->sx + dx);
83 d->setInstantaneousSY(d->sy + dy);